Leveling bridge



June 12, 1951 K J, UNWIN 2,557,058

LEVELING BRIDGE F'led June 28, 1946 Patented June 12,F T951 LEVELING BRIDGE Kenneth J. Unwin, Kenosha, Wis., assignor, by mesne assignments, to Quaker Stretcher Company, Kenosha, Wis., a corporation of Wisconsin Application June 28, 1946, Serial No. 680,186

1 Claim. l

The present invention relates to new and useful improvements in stretching frames and more particularly to improvements in stretching frames adapted for use in drying curtains or other fabrics. Y

In general, the invention contemplates th provision of a stretching frame which includes angularly disposed post and rail members which overlie one another and are relatively adjustable. At least one corner is formed by a post and rail member and a leveling bridge or pin plate is employed at such corner in order to provide a gradual sloping surface to Which the fabric is secured in the overlying or bridging area of the post and rail members. In this type of stretching frame, the leveling bridge usually carries some type of clamping member engageable with the post or the rail, While the bridge itself is engageable with the other post or rail member. Thus, the clamping element and the leveling bridge serve to secure the post and rail members in any predetermined adjusted position. In general, the sloping surface of the leveling bridge has in the past been provided with pins or small nails adapted to penetrate the edge of the fabric for securing the same in this bridging area. Considerable dimculty has been encountered with such constructions in that the penetration of the fabric often results in tearing or mutilation thereof.

An object of the present invention is to effect clamping of the fabric along the leveling bridge without mutilation or damage to the fabric.

A further object of the present invention is to effect clamping of the fabric along the leveling bridge by opposed surface gripping engagement with the fabric and without penetration thereof.

A still further object of the invention is to provide adjustable fabric clamping means along the leveling bridge so as to accommodate uneven edges of the fabric.

'Ihe invention still further aims to provide, in an assembly `of the above type, a leveling bridge and fabric clamping means which are relatively simple in construction and reliable in operation.

The above and other objects of the invention will in part be obvious and will be hereinafter more fully pointed out.

In the accompanying drawing:

Figure l is a perspective View showing -one form of clamping means carried by the leveling bridge which is shown in clamping position with respect to the post and rail members;

Figure 2 is a front elevation of Figure l;

Figure 3 is a side view of Figure 2 as viewed from the left thereof along the line 3 3;

Figure 4 is a View taken along the line 4 4 of Figure 2;

Figure 5 is a view taken along the line 5-5 of Figure 2;

Figure V6 is a fragmentary perspective view showing a modied form of fabric clamping means; and l Figure 7 is a View taken along the line 1-1 of Figure 6.

Referring more in detail to the accompanying drawing, a vertical post l0 is provided along one side thereof with a raised rib portion 10a and along the adjacent side with a reduced portion lllb. The rail H is similarly constructed with a rib portion lla along the lower edge thereof and with a reduced portion Hb along the upper edge thereof. 'Ihe post and rail members overlie one another and are disposed in juxtaposition at substantially right angles to one another, although this is not essential, as the shape of the fabric will determine the angular disposition thereof. The reduced portions 10b, IIb have secured thereto pins I2, I3, respectively, which serve as means for securing the curtain or other fabric to be stretched and dried.

A leveling bridge or pin plate I4 is provided with a lower portion l5 which engages the face of the rib portion Ila of the rail Il and is provided with an inturned flange I6 disposed immediately beneath and engaging the bottom edge of the rail. The upper portion of the leveling bridge, that is, the portion disposed above the rail Il, is gradually inclined downwardly toward and into Contact with the face of the rib portion 10a on the post l0. The upper end of the inclined portion of the bridge may be provided with an inturned guiding flange l'l'adapted to contact the side of the post I0.

The leveling bridge Ill carries clamping means of the type shown in my copending application, led of even date herewith. Detailed description of this clamping means is unnecessary other than to point out that there is provided a C-shaped clamp I3 having inturned flanges I9 adapted to engage the rear face of the post l0. A bracket 20 suitably secured to the clamping portion l5 of the leveling bridge is provided with a tongue 2| (Figure l) adapted to extend into a corresponding opening in the closed end of the clamp I8. There is another tongue 22 {Figure 5) which has the free end thereof bent inwardly to engage in a slot 23 in the adjacent arm of the clamp I8. Thus, when a bolt 24 and wing nut 25 are tightened relative to one another, the post and rail members will be firmly clamped together, and

relative turning of the C-clamp I with respect to the leveling bridge if is prevented by the clamping means described herein.

In the form of the invention shown in Figures l through 5, the leveling bridge i4 is provided with a plurality of fabric clamping devices which will b-e described below. A plate 26 vis secured, as by spot Welding, to the inner face of the leveling bridge across the upper end thereof, This plate is provided with an outwardly turned end which `of the clamping member 33.

provides a flange portion 26a, having an aperture therethrough for receiving the threaded end of a bolt 2l. The opposite end of the bolt 21 is provided with a head adapted for engagement with a flange 28 on a plate 29. A coil spring 39 encircles the bolt 2'l and is disposed between the flanges 26a and 28 to normally -urge the same apart. A wing nut 3l threadedly engages the end of the bolt 21 and is for `the purposeof electing adjustment of the plate 29 inwardly or outwardly with respect to the inclined edge of the leveling bridge where the fabric is secured. The outer end of the plate 29 carries an outwardly extending bolt 32 which extends through an opening in a U-shaped clamping member 33. A wing nut 39 engages the bolt 32 to elect movement of the U-shaped clamping member 33 against the raction of a coil spring 35 disposed between the plate 29 and the inner surface of the closed end Adjacent the inner leg portion of the U-shaped clamping member, the plate 29 is cut inwardly from opposite sides and the metaltherecf turned slightly outwardly to provide stop lugs 35 which cooperate With the adjacent leg portion of the clamping member to prevent rotation thereof as the wing nut is turned. It will be noted that the outer leg portion of the clamping member is provided with a convex clamping surface 3l (Figure 3) and the fabric is adapted to be clamped between this surface and portion 38u which is apertured to permit the passage therethrough of the threaded end of a bolt 39 -carrying a wing nut 59. The opposite -end of the bolt 39 is provided with a head 39a engaging Van outwardly turned ange el on a plate 92. A coil spring i3 is ydisposed around the bolt 39 between the flanges 33a and 4l so as to normally tend to separate the same. The plate 42, at the free end thereof, is formed with an inwardly and outwardly offset flange 113 (Figure 5) which Vserves as a fabric clamping means. rIhe plate l2 carries upper and lower bolts 49, 45 which extend through the closed ends of upper and lower U-shape'd clamping members 4E, 4l, respectively, the outer leg portions of which provide clamping surfaces adapted to cooperate with the flange portion 93 in securing the edge of the fabric. Coil springs 48 are also disposed around the bolts dil, e and between the plate l2 and the closed ends of the U-shaped clamping members to normally separate the same. In this type of clamp, the surface of the plate 42 at the inner edge of the flange 43, contacts the inner leg portions of the clamping members to prevent rotation thereof during turning of wing nuts 49, 59.

In the form of the invention described above, it will be noted that the upper and lower clamping devices may be adjusted inwardly and outwardly with respect to the leveling bridge by proper manipulation of the wing nuts 3|, lill so as to provide a convenient manner of `securing fabric having an edge which may be slightly uneven. The plates 29 and 52 are loosely carried `by the bolts 2l', 39, respectively, so that the clampa ing devices on these plates may be shifted slightly to neatly accommodate the fabric being stretched.

In the form of the invention shown in Figures 6 and 7, a leveling bridge Illa carries upper and lower clamping members in the form of levers 5|, k52, which are secured to the bridge Ma by rivets 53 vpermitting llimited pivotal movement thereof. 'Both levers 5I, 52 are of stepped or offset configuration so as to provide inwardly extending clamping elements 54, 55, and at the opposite ends thereof laterally extending linger portions 59, 51. Each lever is urged toward a clamping position by coil springs 59 bearing against the undersurfaces vof the vlnger portions 56, 51 `and centered by means of a rivet pin 59. The fabric engaging surface of the upper clamping lever is rounded for the purposes mentioned in connection with the form of the invention shown in Figures l through 5. Both clamping portions 54, 55 of the upper and lower levers are adapted to cooperate with an outwardly extending flange 60 on the leveling bridge for clamping the edge of the fabric.

From the foregoing description, it will be seen that -the present invention provides clamping means on Aa leveling bridge for securing fabric along a gradual incline between overlying .post and rail members. The clamping devices are Ysuch that the fabric is gripped between opposed clamping surfaces without-any penetration of the fabricas is the case with pins. In both for-ms of the invention, the clamping vdevices are under manual control for effecting -the clamping or unclamping of the fabric 'and in the form of the invention shown in Figures l through 5, the clamping devices may be adjusted transversely of the leveling bridge so as to properly accommodate any uneven edges presented Yby the fabric.

I-t is to be clearly understood that various changes in the details of construction and a-rrangement of parts may be made without departing from the scope of the invention as set forth in the appended claim.

Iclaim:

In a fabric stretching frame having -crossed and lrelatively overlying post and rail members, a leveling bridge secured at the intersection between said members, a bracket secured to said leveling bridge and -having an outwardly extending flange adjacent 'one side thereof, a plate extending transversely of said leveling bridge and having an outwardly extending flange portion spaced inwardly of the ange on said bracket, clamping means carried by said plate for clamping the fabric, and means cooperating with said flange portion `and the flange of said bracket for securing the said plate to the leveling bridge.

KENNETH J. UNWIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 555,278 Arbogast et al. 25, .1896 591,421 Palmer et al. Oct. 12, 1897 692,615 Caldwell Feb. 4, 1902 1,613,933 Castleton Jan. 11, .1927 2,043,555 Preston June 911936 2,174,789 Kennedy Oct. 3, 1939 2,236,745 Block Apr. 1, 1941 

